Renal Artery Occlusion

Renal Artery Occlusion

 

Definition

Renal artery occlusion is a blockage of the major arteries that supply blood to the kidneys caused by thrombosis or embolism.

Description

Renal artery occlusion occurs when the flow of blood from the arteries leading to the kidneys becomes blocked by a blood clot or cholesterol emboli. The lack of oxygenation can lead to necrosis (tissue death) and ultimately, chronic kidney failure.

Causes and symptoms

Renal arterial occlusion occurs when a thrombus or embolism (blood clot or cholesterol plaque) breaks free and blocks the arteries leading to one or both kidneys.
Symptoms of an acute renal arterial occlusion may include:
  • hypertension
  • fever
  • sudden pain in the lower back or flank
  • nausea and vomiting
  • protein and/or blood in the urine
An individual with renal arterial occlusion may have no overt symptoms, particularly if only one kidney is affected or if the blockage is only partial. Health problems from secondary complications such as chronic kidney failure may be the first indication that something is wrong.

Diagnosis

The high blood pressure that is sometimes associated with a renal artery blockage may be the first sign that it is present, particularly if the hypertension is not responding to standard treatment. Urine and blood tests may or may not be useful in diagnosing this condition. Blood tests may show an elevated plasma creatinine level. If kidney tissue infarction (cell death caused by a lack of blood supply) has occurred, lactic dehydrogenase (LDH) may also be present in the urine and blood.
An arteriogram, an x-ray study of the arteries that uses a radiopaque substance, or dye, to make the arteries visible under x ray, may also be performed. This test is used with caution in patients with impaired kidney function, as the contrast medium can cause further kidney damage. In patients with whom this is not an issue, a spiral computed tomography (CT) scan with contrast medium may also be used.

Treatment

Occlusions may be treated with anticoagulant (blood thinning) or thrombolytic (clot destroying) drugs. If the blockage is significant, surgical intervention or angioplasty may be required. Between 1996 and 2000, the number of these procedures performed on Medicare patients more than doubled, said a 2004 report.

Key terms

Angioplasty — A non-surgical procedure that uses a balloon-tipped catheter to open a blocked artery.
Artherosclerotic plaque — A deposit of fatty and calcium substances that accumulate in the lining of the artery wall, restricting blood flow.
Atrophy — Cell or tissue wasting or death.
Chronic kidney failure — End-stage renal disease (ESRD); chronic kidney failure is diagnosed as ESRD when kidney function falls to 5-10% of capacity.
Embolism — Blood vessel obstruction by a blood clot or other substance (i.e., air).
Thrombus — Formation of a blood clot within the vascular system. A thrombus becomes an embolism if it breaks away and blocks a blood vessel.

Alternative treatment

Renal arterial occlusion is a serious and potentially life-threatening condition, and should always be treated by a healthcare professional familiar with the disorder.

Prognosis

The outcome of renal arterial occlusion depends on the speed with which it is treated. Once the blood supply is minimized or cut off to the kidney, tissue death soon results, ultimately leading to chronic kidney failure (end-stage renal disease).

Prevention

Atherosclerosis may encourage the formation of cholesterol emboli, a potential cause of renal artery occlusion. Strategies for avoiding vascular disease include eating right, maintaining a desirable weight, quitting smoking, managing stress, and exercising regularly. People prone to emboli from blood clots can take blood thinning drugs to prevent potential emboli from loding in the renal artery.

Resources

Periodicals

Bloch, M. J., and T. Pickering. "Renal Vascular Disease: Medical Management, Angioplasty, and Stenting." Seminars in Nephrology 20, no. 5 (September 2000): 474-88.
"Explosive Growth Seen in Renal Artery Interventional Procedures." Heart Disease Weekly September 26, 2004: 20.
Truelove, Christiane. "First for Pulmonary Embolism." Med Ad News August 2004: 82.

Organizations

American Kidney Fund (AKF). Suite 1010, 6110 Executive Boulevard, Rockville, MD 20852. (800) 638-8299. 〈http://www.arbon.com/kidney/〉.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Natcher Building, 6AS-13K, 45 Center Drive, Bethesda, MD 20892-6600. http://www.niddk.nih.gov.
National Kidney Foundation. 30 East 33rd Street, New York, NY 10016. (800)622-9020. http://www.kidney.org.
References in periodicals archive ?
Renal vein thrombosis and renal artery occlusion usually result in graft loss, but fortunately are rare complications.
Our patient underwent laparoscopic PN for the left sided tumor with renal artery occlusion and WI time was 24 minutes.
We included a case of iatrogenic renal artery occlusion at our institution treated by percutaneous stenting 20 hours after injury.
Caption: FIGURE 1: An illustration showing large type III Crawford thoracoabdominal aneurysm (TAAA) with extensive infrarenal segment thrombosis and left renal artery occlusion (a).
It was unclear whether the renal artery occlusion was due to thromboembolism phenomenon or thrombosis in situ.
Pascual et al., "Use of urinary parameters in the diagnosis of total acute renal artery occlusion," Nephron, vol.
RAS was defined by duplex scanning as having a renal aortic ratio of ≥3.5, a peak renal artery systolic velocity of ≥200 cm/s, or a renal artery occlusion. This criterion can discriminate ≥60% atherosclerotic RAS (ARAS) from <60% RAS accurately.
(4,5) Less commonly, a complete renal artery occlusion may result in decreased attenuation throughout the renal parenchyma with a rim of viable tissue, termed the "rim sign," in the capsule.
Therefore, novel techniques which could both avoid renal artery occlusion and achieve adequate hemostasis are urgently required.
Symptoms of spontaneous thromboembolic renal artery occlusion might be nonspecific and misleading.
Studies have addressed the technical aspects of partical nephrectomy, particularly the impact of ischemic time on renal function.[sup.1,3,4] Partial nephrectomy is commonly performed with renal artery occlusion to control bleeding.[sup.5] Warm ischemic times are ideally kept less than 20 to 30 minutes; use of ice slush to create cold ischemic conditions extends the target time to less than 35 to 55 minutes.[sup.3,6] The use of manual compression of the kidney without vascular occlusion is also reported in the literature.[sup.7] While manual compression avoids any potential vascular pedicle injury, its effect on renal function and recovery is not well-studied.[sup.3,6,7] However, this technique may not be done with a laparoscopic partial nephrectomy.